Reese

Growing under a pine tree is very difficult. Growing something under a pine tree that deer do not eat is even harder. The only thing I can recommend to suit both those criteria is sweet woodruff.

We also have a lot of wild blackberries growing around our pinetrees.

Phlox is gorgeous, but it would need to be in full sun.

Salal (Gaultheria Shallon) would be awesome though I'm not entirely sure about growing it from seed. It's a broadleaf evergreen that can grow and flower in deep shade especially in acidic conditions, like under pine trees. It forms a nice thicket that can get a few feet tall and it produces sweet edible berries!

It's fairly deer resistant too. They're often rated to zone 6a so you're right on the line.